I am running Volumio 2.201 on a Raspberry Pi Zero W with a cheap PCM5102A DAC (configured as pHAT DAC)
The mixer types available are None and Software. If I choose Software, and save, then I lose sound, and shortly after the GUI goes dark and shows the “spinner”. I can still log in with SSH. Volumio.log shows
2017-08-02T08:00:49.120Z - info: CALLMETHOD: audio_interface alsa_controller saveVolumeOptions [object Object]
2017-08-02T08:00:49.130Z - info: CoreCommandRouter::executeOnPlugin: alsa_controller , saveVolumeOptions
2017-08-02T08:00:49.174Z - info: Enable softmixer device for audio device number 1
2017-08-02T08:00:49.186Z - info: Enable softmixer device for audio device number 1
2017-08-02T08:00:49.193Z - info: CoreCommandRouter::volumioStop
2017-08-02T08:00:49.199Z - info: [1501660849193] CoreStateMachine::stop
2017-08-02T08:00:49.206Z - info: [1501660849200] CoreStateMachine::setConsumeUpdateService undefined
2017-08-02T08:00:49.232Z - info: CoreCommandRouter::volumioUpdateVolumeSettings
2017-08-02T08:00:49.243Z - info: Updating Volume Controller Parameters: Device: 1 Name: Hifiberry DAC Mixer: Max Vol: 100 Vol Curve; logarithmic Vol Steps: 10
2017-08-02T08:00:49.263Z - info: Volume configurations have been set
2017-08-02T08:00:49.274Z - info: CoreCommandRouter::executeOnPlugin: alsa_controller , getConfigParam
2017-08-02T08:00:49.281Z - info: CoreCommandRouter::executeOnPlugin: alsa_controller , getConfigParam
2017-08-02T08:00:49.288Z - info: CoreCommandRouter::executeOnPlugin: alsa_controller , getConfigParam
2017-08-02T08:00:49.393Z - info: CoreCommandRouter::volumioUpdateVolumeSettings
2017-08-02T08:00:49.398Z - info: Updating Volume Controller Parameters: Device: 1 Name: Hifiberry DAC Mixer: Max Vol: 100 Vol Curve; logarithmic Vol Steps: 10
2017-08-02T08:00:49.432Z - info: Asound.conf file written
Restarting from the command line appears to take longer than normal. When the system comes back up the GUI shows that the mixer type has been reset to None, and sound is working.
Here is a log file (pulling the plug was unnecessary as the system does restart)